Master the Necrobinder's Osty summon, Doom mechanic, Soul generation, and sacrifice strategies in Slay the Spire 2.
Turn Osty into an unstoppable tank and damage dealer. Dirge pumps 4x summons and Souls when upgraded; Wisps and Spur add HP. Bone Shards sacrifices Osty for 9 AoE and 9 Block—use Bodyguard after to revive. Unleash is mandatory for Act 1. Osty absorbs all attacks; she's unaffected by Necrobinder debuffs.
Generate Souls for massive draw and burst damage. Grave Warden, Capture Spirit, and Severance add Souls; Haunt deals 6 unblockable per Soul played. Devour Life gives Souls per summon—10+ per round when upgraded. Best build for high ascension; cycles fast and scales infinitely.
Apply Doom to enemies; when Doom ≥ HP, they die at end of turn. Countdown applies 6 Doom per turn; Sleight of Flesh deals damage when Doom is applied. Death's Door gives 18 Block when 12+ Doom. Deathbringer and Oblivion scale Doom; pair with Neurosurge for draw and momentum.
Veilpiercer makes the next Ethereal cost 0; Sculpting Strike turns cards Ethereal. Bury costs 4 for 52 damage—Veilpiercer plus Sculpting Strike makes it free. Pull From Below deals 5 per Ethereal played. High setup cost but explosive when assembled.
Defend and Bodyguard until Unleash—this is the core Act 1 loop. Osty absorbs Slam and Preparing hits while you scale. Doom is risky due to the split; Soul builds with Haunt and Grave Warden scale better. Bone Shards deals 9 AoE and gains 9 Block for 1 mana; use Bodyguard after to revive Osty. End of Days trivializes the split slimes.
Osty tanks Guardian hits effectively; Dirge and Wisps pump Osty HP during Defensive Mode. Doom builds with Countdown and Sleight of Flesh bypass Guardian's block—Death's Door gives 18 Block when Doom is 12+. Soul builds cycle with Capture Spirit and Grave Warden; Haunt deals 6 unblockable per Soul played. Borrowed Time enables infinites.
Osty blocks Inferno and multi-hit attacks; focus on Soul generation for draw and burst. Minimize Turn 1 plays to reduce Divider. Devour Life scales Souls every summon; Haunt and Severance deal damage. Grave Warden blocks and adds Souls. End the fight before Burns stack—Invoke gives 3 mana next turn for burst.
The Worm adds status cards; Soul cycling with Capture Spirit, Parse, and Grave Warden helps you draw past them. Dredge pulls 3 from discard—pair with Borrowed Time for infinite setup. Seance transforms curses into Souls. Unleash and Devour Life scale; focus on going infinite or bursting before the deck bricks.
Queen locks cards; Soul builds cycle so fast that locked cards matter less. Snap adds Retain to Dirge, Borrowed Time, or Death's Door—retain key cards to avoid locks. Doom with Countdown and Sleight of Flesh applies damage every turn. Transfigure on Dirge or Severance adds Replay for broken value.
Defend and Bodyguard until Unleash—this is the Act 1 core loop; without it you die. Unleash is S tier.
Borrowed Time is 0 cost, doesn't exhaust; upgrade gives 2 mana. Core infinite enabler; take it always.
Dirge is one of the best cards—4x summons and Souls upgraded. Add Retain via Snap for insane turns.
Grave Warden is the best common; 8 Block plus Soul (Soul+ upgraded). Every deck wants draw.
Soul builds are strongest at high ascension; Haunt deals 6 unblockable per Soul, Capture Spirit enables cycling.
Doom equals instant kill when Doom ≥ enemy HP; Countdown plus Sleight of Flesh applies 26+ damage per turn.
Necrobinder has 66 HP—lowest in the game; Osty is essential. Osty absorbs all attacks; effectively doubles HP.
Devour Life: each summon gains Soul—10+ Souls per round when upgraded. Top of S tier.
End of Days trivializes roaches, centipede, scrolls—one-shot upgraded. Skills at battle start relic is strong.
Friendship costs -2 Strength for +1 mana per turn; Souls, Doom, and Osty don't care about Strength.
Neurosurge: Gain 3, Draw 2, apply 3 Doom to self. High risk, high reward; enables pop-off turns.
Osty is unaffected by debuffs on the Necrobinder—if she has Fragile or -Strength, Osty attacks still hit full.
Browse more strategy guides
Find the best builds
Current build rankings